At present, a lamp or electrical appliance using a plug generally fixes L-pole and N-pole contacts of a plug pin with a cable by welding to achieve electrical connection between the plug pin and the electrical appliance. Under normal circumstances, a material of the plug pin is copper. Because a thermal conductivity of copper is very good, a heat generated during welding the cable can be transferred to a plastic part fixing the plug pin, and the plastic part can be easily deformed by the heat. In addition, welding the cable not only consumes labors and affects productivity but also pollutes the environment due to gas generated during welding, and the gas requires to be pumped away. In a night light/lamp, a cable for L-pole and N-pole of a light source board need to be manually inserted, thereby increasing the cost of producing the product.